Aldo Leopold is remembered as a consummate nature writer, a scientist with a philosophical bent, a naturalist informed deeply by his ecological fieldwork, and as an active citizen and conservationist committed to bringing private and public land management into concord. While many of his contemporaries have faded into obscurity, Leopold’s work continues to inspire scholars and conservation practitioners to think of social and ecological systems as necessarily integrated. The authors in this special issue probe why this is so by focusing on the ethical, religious, and spiritual roots and branches of Leopold’s environmental philosophy and his understandings of land health. I suggest that Leopold’s work continues to endure, and receive growing scholarly and popular attention, because he subtly traversed the realm of metaphysics in his writing, creating a challenging dialogue between the sciences and the humanities.